1. Field of the Invention
This invention relates generally to methods to get crude oil from oil wells in formations that were once considered to be substantially drained dry.
2. Description of the Prior Art
A very substantial amount of oil actually remains in the ground even after there is practically no production under normal conditions and much of the oil remaining in the formation remains there because it is too viscous to flow into the well. Present methods, as far as I am aware, use high pressure streams of water, air or gas, to drive such remaining oil to the surface. With one method of recovery, what are termed "input wells" are drilled around oil wells and the stream of fluid is forced into the input wells through the oil bearing formation and into the production wells. Even with such methods there is a substantial residue of crude oil left in the formation that is not recoverable by these methods or, if recoverable at all, it is at an extremely slow rate and in small amounts or quantities.